The highly Z‐selective asymmetric conjugateaddition of 3‐substituted oxindoles to alkynyl carbonyl compounds has been developed by using scandium complexes of chiral N,N′‐dioxides under mild conditions. The thermodynamically unstable Z‐olefin derivatives were obtained in excellent yields and high enantiomeric and geometric control. The catalyst was also found to be effective in the asymmetric acetylenic
Transition metal-free cross-coupling of furan ring with haloacetylenes
作者:Lyubov N. Sobenina、Denis N. Tomilin、Maxim D. Gotsko、Igor A. Ushakov、Boris A. Trofimov
DOI:10.1016/j.tet.2018.02.024
日期:2018.3
menthofuran, a naturally abundant compound, it has been shown for the first time that the furanring can be readily cross-coupled with acylhaloacetylenes in the solid Al2O3 powder at room temperature to afford the corresponding 2-ethynyl derivatives in up to 88% yield. The reaction represents a ring closing/ring opening process that includes reversible formation of the intermediate cycloadducts further
以天然丰富的化合物薄荷呋喃为例,首次证明呋喃环可以在室温下与固体Al 2 O 3粉末中的酰卤乙炔很容易地交叉偶联,得到相应的2-乙炔基衍生物产率高达 88%。该反应代表闭环/开环过程,包括中间体环加合物的可逆形成,进一步产生乙炔衍生物并消除HHal。